Process of producing a liquid explosive composition



Patented Sept. 3, 1935 UNITED STATES PATENT orrncr:

PROCESS OF PRODUCING A LIQUID EXPLOSIVE COMPOSITION No Drawing. Application September 15, 1932,

Serial No. 633,309

9 Claims.

This invention relates to a process for the production of a liquid explosive, and more particularly to the production of a nitroglycerin composition of improved properties adapted for use in 5 commercial high explosives of the dynamite type.

Most of the commercial high explosives in practical use at the present time contain nitroglycerin as the principal explosive ingredient. Consequently nitroglycerin is produced for this purpose in very large amounts. The usual method of preparing nitroglycerin is by the nitration of gylcerin with a mixture of sulfuric and nitric acids, separation of the nitroglycerin from the waste acid, and neutralization of the finished product. The nitroglycerin thus prepared is inroduced into dynamites where it is incorporated with the other ingredients, which comprise absorbents, oxidizing agents, stabilizing materials and the like.

One of the disadvantages of nitroglycerin explosives in the past has been their tendency to freeze when exposed to winter temperatures. To prevent such freezing of nitroglycerin, it has been the practice to use additional compounds dis- 5 solved in the nitroglycerin for the purpose of lowering the freezing point of the mixture. The materials used for this purpose have included such nitrated products as ethylene glycol dinitrate, tetranitrodiglycerin, nitrated sugars, aromatic nitrocompounds and the like. tions serve the desired purpose, when dissolved in nitroglycerin after their preparation by themselves, a common method of obtaining the solution of these materials in nitroglycerin has been to dissolve the unnitrated material in the glycerin and then to carry out the nitration of the two ingredients together. This latter method has been followed particularly in the case of the nitrated sugars, ethylene glycol dinitrate and tetranitrodiglycerin.

The object of the present invention is the production of a liquid explosive ingredient, relatively diflicult to freeze under ordinary atmospheric conditions. A further object is a nitroglycerin composition, having improved properties and adapted for use in dynamite compositions. A still further object is such a nitroglycerin composition containing aromatic nitrocompounds dissolved therein. Additional objects will be described as the invention is further disclosed.

I have found that a liquid explosive composition of very desirable properties is obtained if glycerin and the mononitro derivative of an aromatic hydrocarbon are nitrated in one and the same op- 5 eration. While various nitro derivatives are While such addiavailable for such use, I prefer to use mononitrotoluene, since the resulting nitroglycerin composition has the properties desired and the relative proportions of the different ingredients in the final composition can be readily controlled.

The glycerin and the mononitrotoluene may be mixed in the proportions desired, previous to nitration. This is not the most satisfactory procedure, however, since the solubility of mononitrotoluene in glycerin is very slight and a mixture would be obtained in which segregation of the separate components would take place on standing, unless special preventive measures were taken. I prefer, therefore, to add at least a portion of the glycerin to the nitrating acid first, and then add the nitrotoluene. This procedure has the advantage that the nitration of the glycerin takes place when the nitrating acid approximates the original composition, while the nitration of the mononitrotoluene takes place after the acid has become diluted by the water formed in the nitration reaction and the nitric acid content has been lowered. Such an acid composition is very suitable for the nitration of mononitrotoluene to dinitrotoluene. I may, if desired, add all the glycerin to the nitration acid first, and then add the mononitrotoluene, or I may add a portion of the glycerin, substantially 50%, for example, then the mononitrotoluene, followed by the remainder of the glycerin.

While various proportions of glycerin and mononitrotoluene may be used for nitration together, to produce a liquid explosive composition of the desired properties, I find a suitable range of the two materials for nitration to comprise 2.5 to 38 parts of mononitrotoluene and 97.5 to'62 parts of glycerin. Using such ranges of the initial unnitrated materials, the compositions obtained after nitration comprise substantially 1.25 to 25 parts of dinitrotoluene, and 98.75 to 75 parts of nitroglycerin respectively.

The following illustrates one specific example of my invention, as carried out in practice:

One thousand parts by weight of a mixed acid of the approximate composition, 52% total H2SO4, 48% HNO3, is introduced into a suitable nitrating vessel, provided with agitation and with means for cooling, for example by brine coils or the like. The acid mixture is cooled to a temperature of approximately 36 F. and about 211 parts of glycerin are added slowly to the acid, with agitation and proper control of the temperature. After the addition of the glycerin, 40 parts of mononitrotoluene in liquid form are added. When the nitration is completed, the nitrated charge is separated from the acid solution by the usual procedure, and the acid nitroglycerin composition is washed with water and weak alkali solution, sodium bicarbonate for example, until completely neutral. Using the proportions of mixed acid and unnitrated materials as given above, approximately 530 parts of a nitrated material is obtained consisting of approximately 9.4% dinitrotoluene and 90.6% nitroglycerin.

While I have described the conitration of glycerin and mononitrotoluene or other mononitro derivative of an aromatic hydrocarbon in the foregoing, it Will now be apparent that my invention is applicable also to the nitration of aliphatic alcohols other than glycerin, containing at least two hydroxy groups, which alcohols are capable of forming liquid nitric esters.on nitration, such for example as ethylene glycol. Similarly, the mononitrotoluene may be nitrated with a solution in glycerin of other unnitrated materials such as ethylene glycol, sugars, chlorhydrins, polymerized glycerin,and the like.

vMononitrotoluene or other mononitro compound of an aromatic hydrocarbon from various sources may be used. I find, however, that a particularly desirable material for this purpose is the composition obtained in my copending application, Serial No. 632,183, filed September 8, 1932, covering the denitration of nitroglycerin spent acid by toluene or other aromatic hydrocarbon. The resulting product from this treatment comprises a mononitro-compound, containing in solution a small amount of nitroglycerin. The use of the present invention in conjunction with the process covered in my copending application has many economical advantages, and permits a desirable utilization of by-product materials usually available in large quantities at explosive plants.

, While I have described my invention in detail in the foregoing, it will be understood, however, that many variations within the scope thereof may be made without departing from the spirit of the invention. I intend, therefore, to be limited only as indicated in the following patent claims:

I claim:

1. The process forthe production of a liquid explosive composition comprising the conitration. of an aliphatic alcohol, containing at least two hydroxyl groups and forming a liquid nitric ester,

and a mononitro derivative of an aromatic hydrocarbon, said aliphatic alcohol and mononitrocompound being added separately to the nitrating acid prior to mixing.

2. The process for the production of a liquid explosive composition comprising the conitration of an aliphatic alcohol, containing at least two hydroxyl groups and forming a liquid nitric ester, and mononitrotoluene, said aliphatic alcohol and mononitrotoluene being added separate to the nitrating acid prior to mixing.

3. The process for the production of a liquid explosive composition comprising the conitration of glycerin and mononitrotoluene, said materials being added separately to the nitrating acid prior to mixing.

4. The process for the production of a liquid explosive composition which comprises introducing glycerin into a nitrating acid solution and then introducing a mononitro derivative of an aromatic hydrocarbon into thesame nitrating solution.

5. The process for the production of a liquid explosive composition which comprises introducing glycerin into a nitrating acid solution and then introducing mononitrotoluene into the same nitrating solution.

6. The process for the production of a liquid explosive composition comprising the conitration oi glycerin and mononitrotoluene, at least 50% of the glycerin for nitration being added prior to the addition of the mononitrotoluene.

7; The process for the production of a liquid explosive composition comprising the 'conitration of 2.5 to 38 parts of mononitrotoluene and 97.5 to 62 parts of glycerin, said glycerin and mononitrotoluene being added separately to the nitrating acid prior to mixing.

8. The process for the production of a liquid explosive composition, which comprises introducing glycerin into a nitrating acid solution and then introducing mononitrotoluene into the same nitrating solution, said glycerin and mononitrotoluene being present in such proportions as to give a liquid nitration product containing 1.25 to 25 parts of dinitrotoluene and 98.75 to parts of nitroglycerin.

9. The process according to claim '7, in which at least 50% of the glycerin for nitration is added prior to the addition of the mononitrotoluene.

' JAMES B. CASTNER. 

